Due to the economic recession, the Metropolitan Police Department’s spending has been under increased scrutiny and a “Special Accounting Department” was formed. Madoka, a police officer with the Special Accounting Department, is dispatched to Manmachi Police Station, a station under the jurisdiction of the Metropolitan Police Department that is known to be loose with money and full of scandals. She is strict with the detectives about expenses, and aloof when it comes to cases. She is only passionate about money and can often be heard saying “I won’t forgive even a single yen unaccounted for!” However, Yukawa, a hot-blooded veteran detective who will go to any lengths to solve a case, often resulting in costly property damage and expensive deals with shady informants.

While investigating a sudden murder, Yukawa discovers the victim’s wallet. Security camera footage and receipts reveal that the victim should have had exactly 4 coins of one yen, but there was only 3 coins left in the wallet. Madoka can’t help her concern over the “missing yen,” so she begins her own investigation…

Madoka and Yukawa, a penny-pinching police officer and a hot-headed detective with completely opposite personalities hilariously sometimes clash and sometimes cooperate to solve crimes.